gravitational waves tagged posts

Black Hole Billiards in the Centers of Galaxies

Illustration of a swarm of smaller black holes in a gas disk rotating around a giant black hole . Interactions between three black holes, such as those shown in the foreground, occur relatively often and will with high probability result in a merger on a non-circular orbit (credit: J. Samsing/Niels Bohr Institute)

Researchers provide the first plausible explanation to why one of the most massive black hole pairs observed to date by gravitational waves also seemed to merge on a non-circular orbit. Their suggested solution, now published in Nature, involves a chaotic triple drama inside a giant disk of gas around a super massive black hole in a galaxy far, far away.

Black holes are one of the most fascinating objects in the Universe, but our knowledge of them is still limited — especi...

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Gravitational ‘Kick’ may explain the Strange Shape at the Center of Andromeda

Click to enlarge: Graphic showing the orbit of stars around a supermassive black hole before, left, and after, right, a gravitational “kick.” (Credit: Steven Burrows/JILA)

When two galaxies collide, the supermassive black holes at their cores release a devastating gravitational “kick,” similar to the recoil from a shotgun. New research led by CU Boulder suggests that this kick may be so powerful it can knock millions of stars into wonky orbits.

The research, published Oct. 29 in The Astrophysical Journal Letters, helps solve a decades-old mystery surrounding a strangely-shaped cluster of stars at the heart of the Andromeda Galaxy. It might also help researchers better understand the process of how galaxies grow by feeding on each other.

“When scientists first looked at Andromeda,...

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Astrophysicists detect First Black Hole-Neutron Star Mergers

A long time ago, in two galaxies about 900 million light-years away, two black holes each gobbled up their neutron star companions, triggering gravitational waves that finally hit Earth in January 2020.

Discovered by an international team of astrophysicists including Northwestern University researchers, two events—detected just 10 days apart—mark the first-ever detection of a black hole merging with a neutron star. The findings will enable researchers to draw the first conclusions about the origins of these rare binary systems and how often they merge.

“Gravitational waves have allowed us to detect collisions of pairs of black holes and pairs of neutron stars, but the mixed collision of a black hole with a neutron star has been the elusive missing piece of the family picture...

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A Giant Black Hole keeps Evading Detection and scientists can’t explain it

This composite image of the galaxy cluster Abell 2261 contains optical data from NASA's Hubble Space Telescope and Japan's Subaru Telescope showing galaxies in the cluster and in the background, and data from NASA's Chandra X-ray Observatory showing hot gas (colored pink) pervading the cluster. The middle of the image shows the large elliptical galaxy in the center of the cluster.
This composite image of the galaxy cluster Abell 2261 contains optical data from NASA’s Hubble Space Telescope and Japan’s Subaru Telescope showing galaxies in the cluster and in the background, and data from NASA’s Chandra X-ray Observatory showing hot gas (colored pink) pervading the cluster. The middle of the image shows the large elliptical galaxy in the center of the cluster.
(Image: © X-ray: NASA/CXC/Univ of Michigan/K. Gültekin; Optical: NASA/STScI/NAOJ/Subaru; Infrared: NSF/NOAO/KPNO)

An enormous black hole keeps slipping through astronomers’ nets. Supermassive black holes are thought to lurk at the hearts of most, if not all, galaxies...

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